<!DOCTYPE html>
<html>

<head>
    <meta name="applicable-device" content="pc,mobile">
    <meta http-equiv="Cache-Control" content="no-transform ">

    <style>
        /* html {
            font-size: 625%;
        }

        body {
            font-size: 0.16rem;
        }

        .test {
            font-size: 0.24rem;
        }

        .test1 {
            font-size: 24px;
        }

        .block {
            width: 1rem;
            height: 1rem;
            background: red;
        }

        .block1 {
            width: 100px;
            height: 100px;
            background: yellow;
        }

        .father {
            font-size: 20px;
        }

        .father .son {}

        .father .son .little-son {
            font-size: 1.2em;
        } */
        .image {
            max-width: 100%;
            /* max-width: 100%;
            width: 100%;
            height: auto;
            object-fit: contain; */
        }
    </style>
</head>

<body>
    <!-- <div class="test">测试</div>
    <div class="test1">测试</div>
    <div class="block">测试</div>
    <div class="block1">测试</div>

    <div class="father">
        父元素
        <div class="son">
            子元素
            <div class="little-son">
                孙元素
            </div>
        </div>
    </div> -->

    <div>
        <!-- <img class="image" src="../source/images/bg/640.jpg" srcset="../source/images/bg/642.jpg 1024w, ../source/images/bg/643.jpg 640w, ../source/images/bg/6411.jpg 320w"
        sizes="(max-width: 640px) 100vw, (max-width: 960px) 50vw, calc(100vw / 3)"> -->

        <picture>
            <source media="(max-width:640px)" srcset="../source/images/bg/640.jpg 2x, ../source/images/bg/644.jpg 1x " />
            <source media="(max-width:960px)" srcset="../source/images/bg/641.jpg 2x, ../source/images/bg/645.jpg 1x" />
            <source srcset="../source/images/bg/642.jpg 2x, ../source/images/bg/646.jpg 1x" />
            <img class="image" src="../source/images/bg/643.jpg" alt="">
        </picture>
    </div>
</body>

</html>